memory: jz4780_nemc: Add support for the JZ4740

Add support for the JZ4740 SoC from Ingenic.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>